A witness at the church also told a local CBS affiliate that a toddler is also among the victims.

Wilson County Commissioner Albert Gamez Jr. told CNN he was devastated by the news.

“My heart is broken," Gamez said. "We never think where it can happen, and it does happen. It doesn't matter where you're at. In a small community, real quiet and everything, and look at this, what can happen.”

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Texan Governor Greg Abbott has tweeted his shock.

"Our prayers are with all who were harmed by this evil act. Our thanks to law enforcement for their response."

President Donald Trump also tweeted about the attack and said he was "monitoring the situation closely" from Japan, where he is currently visiting.

May God be w/ the people of Sutherland Springs, Texas. The FBI & law enforcement are on the scene. I am monitoring the situation from Japan.

The area outside the church has been taped off by police and FBI, with family and friends unable to enter.

A representative for the Connally Memorial Medical Center confirmed to TIME that multiple victims with gunshot wounds were being treated at the hospital, but she was unable to give further details on the exact number, their conditions or their injuries.

Two women hug near the church where more than 20 people are feared dead after a shooting. Image via AP.

The current death toll makes the attack the fourth most fatal mass shooting in modern US history, and the deadliest mass killing at a house of worship.